1. Field of the Invention
The present invention relates to an image processing technique.
2. Description of the Related Art
An electrophotographic device using toner is readily influenced by temporal change. Even a high-end device which features high color reproducibility, when not used for a prolonged period of time, becomes poorer than a new office device in terms of color reproducibility. To solve this problem, the user of a conventional device executes calibration at an arbitrary time point to perform color correction for absorbing the fluctuation amount of color reproducibility upon a temporal change. However, even when performing color correction by calibration, the user cannot determine the timing to perform calibration.
To specify the timing to execute calibration, there is a technique of recording the time when calibration was done, and obtaining the time elapsed after the previous calibration and the fluctuation amount of color reproducibility. For example, Japanese Patent Laid-Open No. 2006-168200 proposes a technique of prompting the user to execute calibration in accordance with the elapsed time and the fluctuation amount of color reproducibility.
Electrophotographic devices have recently been developed to be affordable and compact. It is increasingly becoming popular to introduce a plurality of devices into one office. At the same time, the development of the network technology makes it possible to build a system which allows the user to freely select an output device.
However, a conventional network environment is premised on that the user performs processing at an arbitrary timing. A device selected by the user to output data may not always achieve optimum color reproducibility. Especially the fluctuation amount upon a temporal change differs between devices. Even a high-end device having excellent color reproducibility may suffer a large fluctuation amount of color. Even an office device poorer in color reproducibility than a high-end device may exhibit a small fluctuation amount of color.
The fluctuation amount in each device differs for each color. An electrophotographic device uses, for example, different, cyan, magenta, yellow, and black coloring materials, and the degree of deterioration upon a temporal change is also different for each. For a mixture of these coloring materials, the fluctuation amount further changes from that of a single color. Since the fluctuation amount of a device differs for each color it uses, the best device for printing a particular document changes depending on the color distribution of the document.
For this reason, the user can neither know a device optimum for document copying or data output, nor effectively utilize network resources.